Fiber-reinforced ceramic matrix composites (“CMCs”) can exhibit exceptional high temperature properties such as high strength, modulus, and toughness. These properties result from the incorporation of high strength fibers into a stable matrix. The high strength fibers may have a coating which creates a weak interface between the fibers and the matrix material. The fibers are typically incorporated into the composite in fiber tows, which are bundles of individual fiber filaments. Each fiber tow may remain as a discrete entity during CMC processing as opposed to having the individual fiber filaments being distributed uniformly throughout the composite.
The weak interface between the fibers and the matrix material enables debonding of the fibers from the matrix, allowing for crack deflection, bridging and enhanced material strength and toughness.